Answer:
a) 2.94 N
b) 4.90 N
Explanation:
Let us assume that the weight of the ball is 0.98 N
Solution:
a) An object’s gravitational potential energy depends on two factors which are height and its weight (or mass). The equation for gravitational potential energy (PE) is given as:
Potential energy = weight (w) * height (h)
PE = wh
Potential energy at 2 m shelf = weight * height = 0.98 N * 2 m = 1.96 N
Potential energy at 5 m shelf = weight * height = 0.98 N * 5 m = 4.90 N
The work needed to lift the ball from the 2-m shelf to the 5-m shelf = Potential energy at 5 m shelf - Potential energy at 2 m shelf
The work needed to lift the ball from the 2-m shelf to the 5-m shelf = 4.90 N - 1.96 N = 2.94 N
b) Potential energy at 5 m shelf = weight * height = 0.98 N * 5 m = 4.90 N
Answer:
D species
Explanation:
According to the most widely used species definition, the biological species concept, a species is a group of organisms that can potentially interbreed, or mate, with one another to produce viable, fertile offspring. In this definition, members of the same species must have the potential to interbreed.
Answer:
work done by the force, W = -147.97 J
Given:
displacement of the box, s = 4.73 m
angle between force and displacement, 
Force, F = 39.7 N
Solution:
Work done by the force can be expressed as the dot product of Force, F and displacement 's' is given by:
W = Fscos
W = 39.7
W = -147.97 J
where negative sign indicates that work is done on the block
<span>We know that an object in moving with acceleration follow the rule according that
the distance covered will be : d = Vi*t + 1/2*a*t^2
where d is distance, Vi is initial speed, and a is acceleration
Then after 1 km which is 1000 metres we have:
1000 = Vi *71.2 + 1/2*0.0499*(71.2)^2
Vi = (1000-1/2*0.0499*(71.2)^2)/71.2 = 1000/71.2 - 1/2*0.0499*71.2 = 12.27 m/s
Then the car was going at 12.27 m/s when started to accelerate.</span>
