Answer:
The speed of Sam at the bottom is 7.19 m/s.
Explanation:
Given that,
Mass of Sam = 79 kg
Height = 11 m
Length = 120 m
Coefficient of kinetic friction = 0.07
Suppose, an object of mass m is at rest at the top of a smooth slope of height h and length L. The coefficient of kinetic friction between the object and the surface, micro-kilometer , is small enough that the object will slide down the slope if given a very small push to get it started.
We need to calculate the speed at the bottom
Using conservation of energy
Where, m = mass
h = height
L= length
v = speed
g = acceleration due to gravity
Put the value into the formula
Hence, The speed of Sam at the bottom is 7.19 m/s.
Answer:
It takes <u>2.93 s</u> for the object to reach ground from the height of 42 m.
Explanation:
Given:
Displacement of the object is,
As it is dropped, initial velocity of the object is,
Acceleration of the object is equal to acceleration due to gravity and is equal to,
Now, using Newton's equation of motion and plugging in the values, we get:
So, it takes 2.93 s for the object to reach ground from the height of 42 m.
C the milk carton has inertia
Inertia is an object not wanting to start moving when it's staying still, so the milk carton won't want to move and won't topple over
Answer:A
Explanation:
In R-L circuit current is given by
where i=current at any time t
R=resistance
L=Inductance
at t=0 approaches to 1
therefore
i=0
when t approaches to , approaches to zero
thus
thus we can say that initially circuit act as broken wire with zero current
and it increases exponentially with time and act as ordinary connecting wire
Power = VI
⇒ 120 = 6 * I
⇒ I = 120/6 = 20A
Answer is B