Answer:
A) 10 m/s
Explanation:
We know that according to conservation of momentum,
m1v1 + m2v2 = m1u1 + m2u2 ..............(equation 1)
where m1 and m2 are masses of two bodies, v1 and v2 are initial velocity before collision and u1 and u2 are final velocities after collision respectively.
From the given data
If truck and car are two bodies
truck : m1 = 2000 Kg v1 = 5 m/s u1 = 0
car : m2 = 1000 kg v2 = 0 u2 = ?
final velocity of truck and initial velocity of car are static because the objects were at rest in the respective time.
substituting the values in equation 1, we get
(2000 x 5) + 0 = 0 + (1000 x u2)
u2 = 
x 5
= 10 m/s
Hence after collision, car moves at a velocity of 10 m/s
1. 0.2 g/mL
The relationship between mass, density and volume of an object is
where
d is the density
m is the mass
V is the volume
For the object in this problem, we have
m = 10 g
V = 50 mL
Substituting into the equation,
2. 10 mL
In this exercise we know:
- The density of the object: d = 2 g/mL
- The mass of the object: m = 20 g
Therefore, we can re-arrange the previous equation to find the volume:
And substituting values into the equation, we find
Distance is 50 km
Displacement is 10 km
<u>Explanation:</u>
Given:
Distance toward south, x = 25 km
Distance towards west, y = 10 km
Distance towards north, z = 15 km
(a) Total distance, D = ?
Total distance, D = x + y + z
D = 25 + 10 + 15
D = 50km
(b) Displacement, d = ?
Displacement = final position - initial position
= 10 - 0 km
= 10km
Answer: He would reach 7m/s at the distance of 17,5m.
Explanation: In order for us to know how long it takes for the speed to be reached, we use the equation V= Vo + at, with V=7m/s, Vo= 0m/s since you start from rest and a=1.4m/s². T is the time in seconds that we want to find out.
7 = 0 + 1.4t
7 = 1.4t
t= 5s
Now, we want to know the distance this boy reaches in 5 seconds, in a 7m/s speed and accelarating in 1.4m/s². For finding this out, we use another equation, S = So + Vot + (at²)/2, S being the final distance, So = 0m because he started from rest, and the other variables used before.
S = 0 + 0*5 + [1.4*(5²)]/2
S = 0 + 0 + (1.4*25)/2
S = 35/2
S = 17,5m
Answer:
Remember that the number of protons in the nucleus determines an element's identity. Chemical changes do not affect the nucleus, so chemical changes cannot change one type of atom into another. The number of protons in a nucleus does change sometimes, however. The identity of the atom, therefore, it is true
