Question

A point mass (1.8 kg) is suspended from the ceiling by a massless string. If the mass is given an initial speed of 1.7 m/s at the bottom, what maximum height does it achieve? (Assume its initial height represents h=0)(Give your answer to 3 sig figs.) 0.147 m Computer's answer now shown above. You are correct. Your receipt no. is 165-5106 Previous Tries At the maximum height, what angle does the string make with the vertical direction? Assume the string has a length of L =2.5 m. (Give your answer to 3 sig figs. and in the unit of deg)

Answer 1

Assume the string has a length of L =2.5 m it would make an angle of 19.7⁰ on the vertical direction

How to solve for the angle that is made

We have

1 / 2 m v ² = m * g * h

h = v² / 2g

h = 1.7 ² / 2 * 9.8

= 0.147 meters

We are to solve for the angle that is made

cos θ = L -h / L

such that we would have:

cos θ = 2.5 - 0.147 / 2.5

cos θ = 0.9412

θ = cos⁻¹(0.9412)

= 19.7⁰

Assume the string has a length of L =2.5 m it would make an angle of 19.7⁰ on the vertical direction