A student throws a set of keys vertically upward to his fraternity brother, who is in a window 3.95 m above. The brother's outstretched hand catches the keys 1.40 s later. (Take upward as the positive direction. Indicate the direction with the sign of your answer.) (a) With what initial velocity were the keys thrown? (m/s) (b) What was the velocity of the keys just before they were caught? (m/s)

A student throws a set of keys vertically upward to his fraternity brother, who is in a window 3.95 m above. The brother's outstretched hand catches the keys 1.40 s later. (Take upward as the positive direction. Indicate the direction with the sign of your answer.) (a) With what initial velocity were the keys thrown? (m/s) (b) What was the velocity of the keys just before they were caught? (m/s)

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter3: Motion In Two Dimensions

Section: Chapter Questions

Problem 7OQ: A projectile is launched on the Earth with a certain initial velocity and moves without air...

See similar textbooks

Similar questions

The world long jump record is 8.95m. Treated as a projectile, what is the maximum range obtainable by a person if he has a take off speed of 9.5m/s? Assume the motion is on level ground and the angle is 45 degrees.
In the projectile experiment if an object of initial speed 60m/s is thrown in angle 30 horizontal, The maximum distance vertically traveled (height) through motion is: (g=10m/s2)
A projectile is launched on the Earth with a certain initial velocity and moves without air resistance. Another projectile is launched with the same initial velocity on the Moon, where the acceleration due to gravity is one-sixth as large. How does the range of the projectile on the Moon compare with that of the projectile on the Earth? (a) It is one-sixth as large. (b) It is the same. (c) It is 6 times larger. (d) It is 6 times larger. (e) It is 36 times larger.
Compare the time in the air of a basketball player who jumps 1.0 m vertically off the floor with that of a player who jumps 0.3 m vertically.
Which of the following statements are true of the time of flight for a projectile? List all that apply. The time that a projectile is in the air is dependent upon the horizontal component of the initial velocity. The time that a projectile is in the air is dependent upon the vertical component of the initial velocity. For a projectile which lands at the same height that it is projected from, the time to rise to the peak is equal to the time to fall from its peak to the original height. For the same upward launch angles, projectiles will stay in the air longer if the initial velocity is increased. Assume that a kicked ball in football is a projectile. If the ball takes 3 seconds to rise to the peak of its trajectory, then it will take 6 seconds to fall from the peak of its trajectory to the ground.
As soon as a ball was allowed to fall from rest from height h, a second ball was thrown upwards from the ground in the vertical direction. For two balls to meet at height h / 2, what should the initial velocity of the second ball be?
To find the height of an overhead power line, you throwa ball straight upward. The ball passes the line on the way upafter 0.75 s, and passes it again on the way down 1.5 s after itwas tossed. What are the height of the power line and the initialspeed of the ball?
A player passes a basketball to another player who catches it atthe same level from which it was thrown. The initial speed of theball is 7.1 m>s, and it travels a distance of 4.6 m. What were (a) theinitial direction of the ball and (b) its time of flight?
se the position equation s = −16t2 + v0t + s0 where s represents the height of an object (in feet), v0 represents the initial velocity of the object (in feet per second), s0 represents the initial height of the object (in feet), and t represents the time (in seconds). A projectile is fired straight upward from ground level (s0 = 0) with an initial velocity of 128 feet per second. (b) When will the height be less than 128 feet? (Only consider the time from launch to landing. Enter your answer using interval notation.)
Which of the following statements INCORRECTLY describes the horizontal motion of a projectile? •The horizontal motion has non-zero acceleration. •The graph of its horizontal velocity as a funtion of time is a horizontal line. •The horizontal velocity is constant •The graph of its horizontal position as a function of time is a straight line with non-zero slope.
Use a graphing utility to obtain the path of a projectile launched from the ground (h = 0) at the specified values of θ = 35°, v0 = 300 feet per second. In the exercise, use the graph to determine the maximum height and the time at which the projectile reaches its maximum height. Also use the graph to determine the range of the projectile and the time it hits the ground. Round all answers to the nearest tenth.
A young girl standing on a bridge throws a stone with an initial velocity of 12 m/s at a downward angle of 45° to the horizontal, in an attempt to hit a block of wood floating in the river below. If the stone is thrown from a height of 20 m and it just reaches the water when the block is 13 m from the bridge, does the stone hit the block?