A car driving up a hill at a constant speed experiences no change in its kinetic energy while it's potential energy increases with increasing height, thus none of the options are correct.
Understanding the concept
Consider a car moving up the hill at a constant speed as shown in the figure below. The following forces act on the car:
- N is the normal reaction force acting in an upward direction
- f_s is the static friction force exerted due to friction between the road and the tires of the car
- f_k is the rolling friction force in the direction opposing that of the tire
- mg is the force acting in a downward direction.
- θ is the angle of inclination.
Here as the car is moving up the hill at a constant speed, the net force exerted on the car is zero. Also, the kinetic energy of the car will not change as its velocity is constant and the potential energy will change with increasing height. Thus, none of the given options are correct.
Learn more about motion on an incline here:
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Yes, it's true.
But 2nd Newton Law always come to play when the horse is to move forward because obviously the forces interact antagonistically and mass has to be accounted for.
That's what I think. Hope it's right, all the best.
Change minutes to hrs, divide by 60:
30 min = .50 hrs
45 min = .75 hrs
12 min = .20 hrs
----------------
total + 1.45 hrs, total travel time
:
let a = average speed for the trip
:
Write a dist equation, dist = speed * time
:
80(.5) + 100(.20) + 40(.75) = 1.45a
40 + 20 + 30 = 1.45a
90 = 1.45a
a =
a = 62.069 km/h, for the entire trip
and
90 km is the total distance
Answer:
Shown by explanation;
Explanation:
The heat of the sample = mass ×specific heat capacity of the sample × temperature change(∆T)
Assumption;I assume the mass of the samples are : 109g and 192g
∆T= 30.1-21=8.9°c.
The heat of the samples are for 109g are:
0.109 × 4186 × 8.9 =4060.84J
For 0.192g are;
∆T= 67-30.1-=36.9°c
0.192 × 4186×36.9=29656.97J
Answer:
N = 6.67 N
Explanation:
The frictional or frictional force is a force that arises from the contact of two bodies and opposes movement.
The friction is due to imperfections and roughness, mainly microscopic, that exist on the surfaces of the bodies. Upon contact, these roughnesses engage with each other making movement difficult. To minimize the effect of friction, either the surfaces are polished or lubricated, since the oil fills the imperfections, preventing them from snagging.
As the frictional force depends on the materials and the force exerted on one another, its magnitude is obtained by the following expression:
f = μ*N Formula (1)
where:
f is the friction force (N)
μ is the coefficient of friction
N is the normal force (N)
Data
f = 0.2 N : frictional force between the steel spatula and the Oiled Steel frying pan
μ = 0.03 :coefficient of kinetic friction between the two materials
Calculating of normal force
We replace data in the formula (1)
f = μ*N
0.2 = 0.03*N
N = 0.2 / 0.03
N = 6.67 N
