Mechanics | Relativity Answers

what is the total energy of the 0.15kg tennis ball right when serena hits it if it starts at 1.4 meters and travels upward at 35.0 m/s?

Serena williams serves a tennis ball with a velocity of 35.0 m/s upward. if the ball has a mass of 0.15 kg, what is the kinetic energy of the ball?

if the 0.15 kg tennis ball starts at 1.4 meters off the ground what is the tennis ball’s beginning gravitational potential energy?

Trolley with a mass of 15 kg is accelerated at 3 m/s2. What force is needed to do this?

You drop a rock from rest out of a window on the top floor of a building, 40.0m above the ground. When the rock has fallen 4.20m, your friend throws a second rock straight down from the same window. You notice that both rocks reach the ground at the exact same time. What was the initial velocity of the rock that your friend threw? (Assume upward is the positive direction and downward is negative. Indicate the direction with the sign of your answer).

A weightless rod CD, 1.0m long is acted upon by horizontal forces of 2N,2N, 4N, 8N is shown in the figure. What force will be necessary to produce equilibrium?

Q.1 A hydraulic circular rod having a 100mm diameter and 2m long is pulled by a force of 200 N. It moves with a constant velocity within a circular hollow tube of 101mm internal diameter. The clearance of 0.5mm between the rod and the tube is filled with oil of specific gravity 0.8 and kinematic viscosity 400 mm2/s as shown in the figure below. Determine the velocity of the rod in units of m/s.

Vector L= 10m, 24* south of west
Vector H= 20m, 65* north of south
Find L+H=R
Find theta

A pyramid has a height of 516 ft and its base covers an area of 15.0 acres (see figure below). The volume of a pyramid is given by the expression
V = 1/3 bh
where B is the area of the base and h is the height. Find the volume of this pyramid in cubic meters. (1 acre = 43,560 ft2)

An airplane flies 20km in a direction 60 degree north of east then 30 km straight east and then 16km straight north .How far and what direction is the plane from the stating point?