Recent content by sam2k2002

Torque--Sign hanging from a cable Homework Statement A 120cm-wide sign hangs from a 5.4 kg, 200cm-long pole. A cable of negligible mass supports the end of the rod as shown in the figure What is the maximum mass of the sign if the maximum tension in the cable without breaking is 330N...

so g=v^2/r ?

How do I calculate the orbital speed? I assume after I get that, i can compute the change in kinetic energy?

I'm not sure how to do that.. I get: U_g(10km) = -2.67*10^17 U_g(100km) = -2.67*10^16 the difference is only 26.7J... that can't be right.

Homework Statement A 6000 kg lunar lander is in orbit 10 km above the surface of the moon. It needs to move out to a 100 km-high orbit in order to link up with the mother ship that will take the astronauts home. How much work must the thrusters do? Homework Equations U_s = -GMm/r F_g =...

The radius was given in the first part of the problem.

Homework Statement You have been visiting a distant planet. Your measurements have determined that the planet's mass is twice that of Earth but the free-fall acceleration at the surface is only one-fourth as large. Radius = 1.8*10^7meters Mass = 1.19484 × 10^25 kilograms Homework...

Nope.. That was my last attempt, the answer turned out to be 3.67. Any idea what we're doing wrong?

Nope, that doesn't work. Here's what i have for the energy equation. Work_thrust = U_g + KE (240N)(.535m) = (11.7kg)(9.81)(.535m) + 1/2(11.7kg)v^2 With that equation I get 3.38m/s, which is wrong. Maybe I'm using the wrong height? The problem asks for the velocity at the height of the...

Homework Statement A 11.7 kg weather rocket generates a thrust of 240 N. The rocket, pointing upward, is clamped to the top of a vertical spring. The bottom of the spring, whose spring constant is 560 N/m, is anchored to the ground. (a) Initially, before the engine is ignited, the rocket...