PHY 101 Module 3 mastery a

A stone of mass m = 1.45 kg is dropped from a height of h = 3.6 m into a basin of water. At a time of t = 1.02 s after hitting the surface of the water, the stone's velocity has decreased by 50%. What is the magnitude of the average force the stone experiences, in newtons, during the time t?

A hot-air balloon of mass 220 kg is descending vertically with downward acceleration of magnitude 1.4 m/s?. How much mass (ballast) must be thrown out to give the balloon an upward acceleration of magnitude 1.4 m/s² (same magnitude but opposite direction)? Assume that the upward force from the air (the lift) does not change because of the decrease in mass. Number i Units

The air exerts a forward force of 10 N on the propeller of a 0.20 kg model airplane. If the plane accelerates forward at 2.0 m/s2, what is the magnitude of the resistive force exerted by the air on the airplane?

What net external force is exerted on a 1350-kg artillery shell fired from a battleship if the shell is accelerated at 1.80 ✕ 104 m/s2? (Enter the magnitude.) NWhat is the magnitude of the force exerted on the ship by the artillery shell? N

A horizontal force, F1 = 55 N, and a force, F2 = 17 N acting at an angle of 0 to the horizontal, are applied to a block of mass m = 3.9 kg. The coefficient of kinetic friction between the block and the surface is uk 0.2. The block is moving to the right. = Randomized Variables F₁ = 55 N F₂=17 N m = 3.9 kg o vi ble. on d ed ed FN=46.72 (b) Solve numerically for the magnitude of acceleration of the block, a in m/s², if 0 = 30°. (a) Solve numerically for the magnitude of the normal force, FN in Newtons, that acts on the block if 0 = 30°. ✓ Correct! a = 15.487 tan() П acos() E 14 sinh() 1 * 1 tanh() cotanh() Degrees O Radians 2 0 VO BACKSPACE sin() cos() cotan() asin() atan() acotan() cosh() Submit Hint . Feedback 7 85 9 6 3 I give up! • DEL HOME ← END y. CLEAR X Hk m 0

What is the net external force on an object in freefall on Earth if you were to neglect the effect of air? O The net force iszero. O The net force is upward with magnitude mg. The net force is downward with magnitude mg. O The net force is downward with magnitude 9.8 N.

A 3.00-kg object is initially moving northward at 15.0 m/s. Then a force of 15.0 N, toward the east, acts on it for 3.70 s.     What is the direction of the final velocity? Enter the angle in degrees where positive indicates north of east and negative indicates south of east.

A2.60 kg block is initially at rest on a horizontal surface. A horizontal force Fof magnitude 6.69 N and a vertical force Pare then applied to the block (see the figure). The coefficients of friction for the block and surface are u, - 0.4 and - 0.25. Determine the magnitude of the frictional force acting on the block if the magnitude of P is (a)8.00N and (b)12.0 N. (The upward pull is insufficient to move the block vertically.) (a) Number Units (b) Number Units

A 3.00-kg object is acted upon by an applied force causing it to move along a rough horizontal plane, with its x 5t² - 1 and y = 3t3 + 2, where x and y are in meters and t is in seconds. The and y coordinates given by x = coefficients of friction between the object and the surface are 0.4 and 0.8. Answer the following questions: a. What are the units of the numerical coefficients? b. Determine the acceleration of the object as a function of time. c. Determine the Net force acting on the object at t = 5s.

A 50.0-kg object is initially moving south at 20.0 m/s. Then a force acts on it for 3.00 s, after which it moves northeast, 45° north of east, also at 20.0 m/s. What are the magnitude and direction of the average force that acted on the object over the 3.00-s interval? (Hint: Recall, F = ma and a = AV.)

Two boats push on a barge at different angles. The first boat exerts a force of 6.9 x 105 N in the x-direction, and the second tugboat exerts a force of 4.7 x 105 N in the y-direction. The mass of t he barge is 7.0 × 106 kg and its acceleration is observed to be 7 x 10−2 m/s2 in the direction shown. What is the drag force of the water on the barge resisting the motion? What is the Resultant Angle?

5. A 3.00-kg object is moving in a plane, with its x and y coordinates given by x = 5t2 -1 and y = 3t³ + 2, where x and y are in meters and t is in seconds. Find the %3| magnitude of the net force acting on this object at t = 2.00 s. Answer: 112 N

Uz (m/s) 2. A 2.75-kg cat moves in a straight line (the x- axis). The figure shows a graph of the x- component of this cat's velocity as a function of 12.0 10.0 8.0 6.0 4.0 2.0 time. (a) Find the maximum net force on this cat. When does this force occur? tr(s) 2.0 4.0 6.0 8.0 10.0 (b) When is the net force on the cat equal to zero? (c) What is the net force at time 8.5 s?

A shot putter throws the 7.26-kg steel ball a horizontal distance of 14.7 m. The shot was released at a height of 2.71 m and the initial velocity made and angle of exactly 45 degrees with horizontal. a) What was the initial speed of the ball in m/s? v = b) If the ball moved 1.82 m (in a straight line) while it was being thrown, then what was the magnitude of the net force, in N, on the ball as it was being thrown? Fnet =

A 3.00-kg object is initially moving northward at 15.0 m/s. Then a force of 15.0 N, toward the east, acts on it for 3.30 s. (a) At the end of the 3.30 s, what is magnitude of the object’s final velocity? ___m/s (b)What is the direction of the final velocity? Enter the angle in degrees where positive indicates north of east and negative indicates south of east. (c) What is the change in momentum during the 3.30 s? Take +y to be north and +x to be east. Enter a positive answer if the change in momentum is toward east and a negative answer if the change in momentum is toward west. ____kg·m/s

The coefficient of friction between the tires of Shirley's 1985 Ford Coupe and the dry pavement is 0.74. She doesn't drive the car often because it's becoming an antique, but she took it out for a gentle drive yesterday. While driving, she has to suddenly and forcefully brake when the light turned red. She probably shouldn't have been texting and driving! Her car (mass = 1.22x10° kg) skids to %3D a stop with an acceleration of m/s2. Use the approximation g = 10 m/s2.