Answer:
Eleven seconds.
Explanation:
Two keys are needed to solve this problem. First, the conservation of momentum: allowing you to calculate the cart's speed after the elephant jumped onto it. It holds that:
So, once loaded with an elephant, the cart was moving with a speed of 4.29m/s.
The second key is the kinematic equation for accelerated motion. There is one force acting on the cart, namely friction. The friction acts in the opposite direction to the horizontal direction of the velocity v0, its magnitude and the corresponding deceleration are:
The kinematic equation describing the decelerated motion is:
It takes 11 seconds for the comical elephant-cart system to come to a halt.
Power is the rate of work done or produced by a system. It will have units of Watts which is equivalent to Joules per second. To determine the work or energy produced by the system, we multiply power with time. We do as follows:
Energy = Power x time
Energy = 1500 J/s (2.0 hr) (3600 s / 1 hr)
Energy = 10800000 J
Physical: the raft needs to float, which means what you make the raft out of must be less dense than water.
The raft would need sturdiness- if the raft is frail, the water might break it
Chemical: It can not react with water and it can not be made of a completely soluable substance (something that would dissolve in it like salt)
Answer:
D. 15 m/s downward
Explanation:
v = at + v₀
v = (-9.8 m/s²) (1.5 s) + (0 m/s)
v = -14.7 m/s
Rounded to two significant figures, the answer is D, 15 m/s downward.
A falling object will reach 49 m/s
