What type of path does a moving object follow in the absence of force?

Suppose that Zak's younger cousin, Greta, sees him sliding across the hall and takes off her shoes so that she can slide as well (assume her socks have the coefficient of kinetic friction of 0.250). Instead of getting a running start, she asks Zak to give her a push. So, Zak pushes her with a force of 125 N over a distance of 1.00 m. If her mass is 20.0 kg, what distance d does she slide after Zak's push ends? Remember that the frictional force acts on Greta during Zak's push and while she is sliding after the push.

Which one of the following forces is non-conservative? O The electric force The Elastic force O The gravitational force O Air resistance

A parachutist whose mass is 70 kg drops from a helicopter hovering 2500 m above the ground and falls toward the ground under the influence of gravity. Assume that the force due to air resistance is proportional to the velocity of the parachutist, with the proportionality constant b₁ = 30 N-sec/m when the chute is closed and b₂ = 90 N-sec/m when the chute is open. If the chute does not open until the velocity of the parachutist reaches 15 m/sec, after how many seconds will the parachutist reach the ground? Assume that the acceleration due to gravity is 9.81 m/sec². - The parachutist will reach the ground after (Round to two decimal places as needed.) * seconds.