Physics Answers

a person acceleration at 9.80 m/s2 as she falls out of a plane experiences a net force of 1000 N. What is her mass?

Calculations:

1. Suppose a large rock is ejected from a volcano with a speed of 25m/s and at an angle of 35*

the horizontal. If the rock strikes the side of the volcano at an altitude 20m lower than the star

point.

(a) Calculate the time it takes the rock to reach the starting point.

(b) What are the magnitude and direction of the rock's velocity at impact?

Two rods of equal length (0.45 cm) and diameter (1.5 cm) are placed end to end. One rod is aluminum, the other is brass. If a compressive force of 8400 N is applied to the rods, how much does their combined length decrease?

The "human cannonball" has long been a popular and extremely dangerous circus

stunt.

A person with a mass of 45kg starts at rest and leaves the cannon with a final speed of

25m/s after a 1600N force is applied to them by the cannon. For how much time was the

force being applied to the person?

A sound wave of frequency 300 Hz travels with speed 340ms-1 along

the negative x-direction. Each point of the medium moves up and down through a

total distance of 5.0 mm. Determine the necessary parameters to represent the

wave mathematically.

A car is moving on a straight road. The velocity of the car varies with time as shown in the figure. Initially (at t=0) the car was at x=0, where x is the position of the car at any time t. Find acceleration of car at time t=15 sec and t=55 sec

A skater glides along a circular path of radius 2.50m . If she coasts around one half of the circle, find the distance in m from the starting location

An elevator is moving up at a constant velocity of 2.50 m/s the man has a mass of 85.0 kg how large is the force exerts on the man

At the surface of Jupiter’s moon Io the acceleration due to gravity is g=1.81 m/s2 . A watermelon weighs 44.0 N at the surface of the earth. a) What is the mass on the earth’s surface? b) What are its mass and weight on the surface of Io? 

A scale reads 328 N when a piece of brass is hanging from it. What does it read (in N) when it is lowered so that the brass is submerged in water?