The answer is D. i got all the other ones wrong ._.
Answer:
Explanation:
Speed of an object is defined as the ratio of the distance covered by the object to the time taken to cover that distance.
Let 
be the speed of the object.
Let 
be the distance travelled by the object.
Let 
be the time taken by the object.
So,
s=
So,the speed of the car is 
Answer:
4m/s2
Explanation:
acceleration=v-u/t...v=12m/s,u=0m/s,t=3sec
a=12-0/3
=4m/s2
Mechanical advantage = ideal mechanical advantage x efficiency = 3.5 x 0.6 = 2.1
The mechanical advantage of the inclined plane is 2.1
(amount of heat)Q = ? , (Mass) m= 4 g , ΔT = T f - T i = 180 c° - 20 °c = 160 °c ,
Ce = 0.093 cal/g. °c
Q = m C ΔT
Q = 4 g × 0.093 cal/g.c° × ( 180 °c- 20 °c )
Q= 4×0.093 × 160
Q = 59.52 cal
I hope I helped you^_^
