3 - b) weight decreases
4 -a) 50 kg as mass is same everywhere
5 - b) 200 dynes
Answer:B
Explanation:
Initial velocity, u=0m/s
Distance,s=20m
a=+g=9.8m/s*s
Using v*v=u*u+2gs
v*v=0+2*9.8*20
v*v=392
v=19.8
When s=20m, v = 19.8m/s
Therefore when v = 10m/s, s= 10*20/19.8
s =10.1m
ANSWER:
F(h)= 230 N is the horizontal force you will need to move the pickup along the same road at the same speed.
STEP-BY-STEP EXPLANATION:
F(h) is Horizontal Force = 200 N
V is Speed = 2.4 m/s
The total weight increase by 42%
coefficient of rolling friction decrease by 19%
Since the velocity is constant so acceleration is zero; a=0
Now the horizontal force required to move the pickup is equal to the frictional force.
F(h) = F(f)
F(h) = mg* u
m is mass
g is gravitational acceleration = 9.8 m/s^2
200 = mg*u
Since weight increases by 42% and friction coefficient decreases by 19%
New weight = 1+0.42 = 1.42 = (1.42*m*g)
New friction coefficient = μ = 1 - 0.19 = 0.81 = 0.81 u
F(h) = (0.81μ) (1.42 m g)
= (0.81) (1.42) (μ m g)
= (0.81) (1.42) (200)
= 230 N
Slower cooling engenders the growth of larger crystals in igneous rocks, thus, your answer should be slow cooling!
Hope this helped!
