Explanation:
Given:
Δx = -100
v = 10
a = 20
To find v₀, use a kinematic equation that's independent of time.
v² = v₀² + 2aΔx
(10)² = v₀² + 2(20)(-100)
100 = v₀² − 4000
v₀² = 4100
v₀ = ±64.0
As your teacher said, v₀ can't be +64.0. So v₀ = -64.0.
Next, to find time, use a kinematic equation that's independent of initial velocity.
Δx = vt − ½ at²
-100 = (10) t − ½ (20) t²
-100 = 10 t − 10 t²
-10 = t − t²
t² − t − 10 = 0
Solve with quadratic formula:
t = [ -(-1) ± √((-1)² − 4(1)(-10)) ] / 2(1)
t = (1 ± √41) / 2
t > 0, so:
t = (1 + √41) / 2
t ≈ 3.70
Answer:
<h2><u><em>
Plants use Nitrogen</em></u></h2>
Explanation:
<h3><em>They use it for nutrients</em></h3>
The heat needed is given by Mcθ , where m is the mass in Kg, c is the heat capacity of aluminium, and θ is the change in temperature.
Specific heat capacity of aluminium is 0.9 j/g°c
thus; Heat = 55 × 0.9 × 72.2
= 3573.9 Joules or 3.574 kJ
Answer : <em>Her weight is lower on Venus because the acceleration due to gravity is lower.</em>
Explanation :
Venus is also called as Earth's twin. This is because both the mass and the size of Earth and Venus are almost same. The acceleration due to gravity on earth is
while on Venus is
.
So, when Shari measure her weight on Venus she found her weight is lower on Venus. This is because the acceleration due to gravity is lower on the surface of Venus as compared to the Earth.
Since, 
i.e. weight depends on g.
<em>So, correct prediction is (b)</em>
Answer:
t = 3.35 s
Explanation:
It is given that,
Mass of a pumpkin, m = 8 kg
It is dropped from a height of 55 m
We need to find the time taken by it to hit the ground.
Initial velocity of the pumpkin, u = 0
Using second equation of motion to find it as follows :

So, it will take 3.35 seconds to hit the ground.