A boat heads north at 30 mph while a steamer heads east at 40 mph at the same time. When is the distance between them 50 mi? Ans
1 answer:
Answer:
1 hour
Explanation:
Speed of the first boat = 30 mph
Speed of the second = 40 mph
The boats will cover different distances but the time taken will be the same.
Time taken by the boats = t
Distance = Speed × Time
Distance covered by the first boat = 30t
Distance covered by the second boat = 40t
Distance between the boats = 50 mi
From the Pythagoras theorem
Time taken by the boats when they are 50 mi away is 1 hour
You might be interested in
Answer:
a. 79.1 N
b. 344 J
c. 344 J
d. 0 J
e. 0 J
Explanation:
a. Since the crate has a constant velocity, its net force must be 0 according to Newton's 1st law. The push force by the worker must be equal to the friction force
on the crate, which is the product of friction coefficient μ and normal force N:
Let g = 9.81 m/s2
b. The work is done on the crate by this force is the product of its force and the distance traveled s = 4.35
c. The work is done on the crate by friction force is also the product of friction force and the distance traveled s = 4.35
This work is negative because the friction vector is in the opposite direction with the distance vector
d. As both the normal force and gravity are perpendicular to the distance vector, the work done by those forces is 0. In other words, these forces do not make any work.
e. The total work done on the crate would be sum of the work done by the pushing force and the work done by friction
Answer:
3.71 m/s
Explanation:
From the law of conservation of linear momentum, since we are neglecting minor energy losses due to friction then we can express it as since all the potential energy is transformed to kinetic energy
Making v the subject of the formula then and here m is the mass of the block, g is acceleration due to gravity, h is the height. Substituting 0.7 m for h and 9.81 for g then we obtain that