Recent content by Parzival

Homework Statement A top is a toy that is made to spin on its pointed end by pulling on a string wrapped around the body of the top. The string has a length of 64 cm and is wrapped around the top at a place where its radius is 2.0 cm. The thickness of the string is negligible. The top is...

Please clarify? I've been stumped for a long time. Following your advice, time = angle/angular velocity But how do I plug it in?

Homework Statement A device can be used to measure the speed of a bullet. The device consists of two rotating disks, separated by a distance of d = 0.850 m, and rotating with an angular speed of 95.0 rad/s. The bullet first passes through the left disk and then through the right disk. It is...

May you please clarify? I've been stumped for a long time.

Homework Statement Two people are standing on a 2.0 m long platform, one at each end. The platform floats parallel to the ground on a cushion of air, like a hovercraft. one person throws a 6.0 kg ball to the other, who catches it. The ball travels nearly horizontally. Excluding the ball, the...

Homework Statement A golf ball bounces down a flight of steel stairs, striking each stair on the way down. The ball starts at the top step with a vertical velocity component of zero. If all the collisions with the stairs are elastic, and if the vertical height of the staircase is 3.00 m...

So: 8000/12 N is the answer. Significant digits yield 6.7*10^2, which is correct!

Fail. 8*10^3. Why thanks?

Fail. So 8.0 * 10^4?

Is it 83000 - 75000 = 1.2 * 10^4?

Homework Statement The motor of a ski boat generates an average power of 7.50 * 10^4 W when the boat is moving at a constant speed of 12 m/s. When the boat is pulling the skier at the same speed, the engine must generate an average power of 8.30 * 10^4 W. What is the tension in the tow rope...

Sorry, I forget. What does capital M represent? I know lowercase m represents the mass, right?

Sorry, I failed miserably. The equation is sqrt(8Mg(hf-h0)/ m) Let me guess. Plug in the numbers; then, multiply this by four to get the original KE, and then solve for the final velocity.

So: v^2 = 8mMg(hf - h0) v = sqrt(8mMg(hf-h0)) but what is h0? Do I assume it is 0 m? And there are two masses: the 0.400 kg one and the 9.00 kg one.

KE = 1/8mv^2 or KE = 1/4mg(hf-h0)