Answer:
B- They both have travelled equal distances in 7 minutes
Hope this helps!
Average speed = (1/2) (beginning speed + ending speed)
= (1/2) ( 13 m/s + 30 m/s )
= (1/2) ( 43 m/s )
= 21.5 m/s
Answer:
The height of the cliff is, h = 78.4 m
Explanation:
Given,
The horizontal velocity of the projectile, Vx = 20 m/s
The range of the projectile, s = 80 m
The projectile projected from a height is given by the formula
<em> S = Vx [Vy + √(Vy² + 2gh)] / g
</em>
Therefore,
h = S²g/2Vx²
Substituting the values
h = 80² x 9.8/ (2 x 20²)
= 78.4 m
Hence, the height of the cliff is, h = 78.4 m
Explanation:
In a vacuum (no air resistance), it doesn't. All falling objects, regardless of mass, accelerate at the same rate.
However, when air resistance is taken into account, heavier objects indeed fall faster than lighter objects, provided they have the same shape and size. For example, a lead ball falls faster than a styrofoam ball.
To understand why, first look at what factors affect air resistance:
D = ½ρv²CA
where ρ is air density,
v is velocity,
C is drag coefficient,
and A is cross sectional area.
As falling objects accelerate, they eventually reach a maximum velocity where air resistance equals weight. This is called terminal velocity.
D = W
½ρv²CA = mg
v = √(2mg/(ρCA))
If we increase m while holding everything else constant, v increases. So two objects with the same size and shape but different masses will have different terminal velocities, with the heavier object falling faster.
Answer:
Explanation:
Magnetic field due to a long current carrying conductor
μ₀ / 4π x 2i / r ( i = current , r = distance of point from wire )
= 10⁻⁷ x 2 x 120 / 6.4 ( i = 120 A , r = 6.4m )
= 37.5 x 10⁻⁷ T .
= 3. 75 X 10⁻⁶ T .
= 3.75 µT.
b )
The direction of this field will be horizontal hence it will affect magnetic needle.
