A motorboat is travelling with a velocity of 40 ft/sec when its motor shuts off at time t = 0. Thereafter its deceleration, due to water resistance, is given by = -k where k is a positive constant. After 10 seconds, the boat's velocity is measured to be 20 ft/sec.
(a) What is the value of k?
(b) When will the boat slow to 5 ft/sec?
A) (a) k = (b) 70 s
B) (a) k = (b) 700 s
C) (a) k = (b) 140 s
D) (a) k = (b) 100 s
E) (a) k = (b) 250 s

Question

A motorboat is travelling with a velocity of 40 ft/sec when its motor shuts off at time t = 0. Thereafter its deceleration, due to water resistance, is given by  = -k  where k is a positive constant. After 10 seconds, the boat's velocity is measured to be 20 ft/sec.
(a) What is the value of k?
(b) When will the boat slow to 5 ft/sec?
A) (a) k = (b) 70 s 
B) (a) k = (b) 700 s 
C) (a) k = (b) 140 s 
D) (a) k = (b) 100 s 
E) (a) k = (b) 250 s

Quizplus · Accepted Answer

The Answer of A motorboat is travelling with a velocity of 40 ft/sec when its motor shuts off at time t = 0. Thereafter its deceleration, due to water resistance, is given by  = -k  where k is a positive constant. After 10 seconds, the boat's velocity is measured to be 20 ft/sec.
(a) What is the value of k?
(b) When will the boat slow to 5 ft/sec?
A) (a) k = (b) 70 s 
B) (a) k = (b) 700 s 
C) (a) k = (b) 140 s 
D) (a) k = (b) 100 s 
E) (a) k = (b) 250 s

A Motorboat Is Travelling with a Velocity of 40 Ft/sec