A 50 kg pole vaulter running at 13 m/s vaults over the bar. Herspeed when she is above the bar is 1.3 m/s. Neglect air resistance,as well as any energy absorbed by the pole, and determine heraltitude as she crosses the bar.
(answer in M)
A skier of mass 66 kg is pulled up a slope by a motor-drivencable.
a)How much work is required to pull him 45 m up a 30° slope(assumed frictionless) at a constant speed of 2.1 m/s? (answer inJ)
b)What power must a motor have to perform this task? (answer inhp)
When a 2.70-kg object is hung vertically on a certain light springdescribed by Hooke's law, the spring stretches 3.06 cm.
a)What is the force constant of the spring? (in N/m)
b)If the 2.70-kg object is removed, how far will the spring stretchif a 1.35-kg block is hung on it?(in cm)
c)How much work must an external agent do to stretch the samespring 6.40 cm from its unstretched position?(in J)
A 50 kg pole vaulter running at 13 m/s vaults over the bar. Herspeed when she is above the bar is 1.3 m/s. Neglect air resistance,as well as any energy absorbed by the pole, and determine heraltitude as she crosses the bar.
(answer in M)
A skier of mass 66 kg is pulled up a slope by a motor-drivencable.
a)How much work is required to pull him 45 m up a 30° slope(assumed frictionless) at a constant speed of 2.1 m/s? (answer inJ)
b)What power must a motor have to perform this task? (answer inhp)
When a 2.70-kg object is hung vertically on a certain light springdescribed by Hooke's law, the spring stretches 3.06 cm.
a)What is the force constant of the spring? (in N/m)
b)If the 2.70-kg object is removed, how far will the spring stretchif a 1.35-kg block is hung on it?(in cm)
c)How much work must an external agent do to stretch the samespring 6.40 cm from its unstretched position?(in J)
