Answer:
The frictional force 
6.446 N
The acceleration of the block a = 6.04 
Explanation:
Mass of the block = 3.9 kg
°
= 0.22
(a). The frictional force is given by
3.9 × 9.81 × 
29.3 N
Therefore the frictional force
0.22 × 29.3
6.446 N
(b). Block acceleration is given by
F = 30 N
= 6.446 N
= 30 - 6.446
= 23.554 N
The net force acting on the block is given by
23.554 = 3.9 × a
a = 6.04
This is the acceleration of the block.
The silver coating on the inner bottle prevents heat transfer by radiation, and the vacuum between its double wall prevents heat moving by convection. The thinness of the glass walls stops heat entering or leaving the flask by conduction.
The downward pull of an object due to gravity is the object’s weight.
The mineral with Mohs hardness would be scratched because the mineral with Mohs 7 hardness is stronger than the Mohs 5 mineral. Eventually, that mineral would turn into dust if you kept rubbing it.
Answer:
21.59 m/s
Explanation:
recall that one of the equations of motions can be expressed as
v² = u² + 2as
where,
v = final velocity (we are asked to find this)
u = initial velocity = 0m/s (because it says that it starts from rest)
a = acceleration = 3.7m/s²
s = distance travelled = 63 m
simply substitute the known values above into the equation:
v² = u² + 2as
v² = 0² + 2(3.7)(63)
v² = 466.2
v = √466.2
v = 21.59 m/s
