As per Definition of acceleration we know that rate of change in velocity of object is known as acceleration

so when we apply push on an object that push or applied force will change the velocity of object always
so correct answer must be
a.) changed the velocity
There’s many terms to it
1 : to keep in a safe or sound state He conserved his inheritance. especially : to avoid wasteful or destructive use of conserve natural resources conserve our wildlife. 2 : to preserve with sugar. 3 : to maintain (a quantity) constant during a process of chemical, physical, or evolutionary change conserved DNA ...
Answer:
a

b

Explanation:
From the question we are told that
The child's weight is 
The length of the sliding surface of the playground is 
The coefficient of friction is 
The angle is 
The initial speed is 
Generally the normal force acting on the child is mathematically represented as
=> 
Note 
Generally the frictional force between the slide and the child is

Generally the resultant force acting on the child due to her weight and the frictional force is mathematically represented as

Here F is the resultant force and it is represented as 
=> 
=> 
=> 
=>
So

=> 
Generally the heat energy generated by the frictional force which equivalent tot the workdone by the frictional force is mathematically represented as

=> 
=> 
Generally from kinematic equation we have that

=> 
=> 
=> 
Answer:
Professor Hawking had just turned 21 when he was diagnosed with a very rare slow-progressing form of ALS, a form of motor neurone disease (MND). He was at the end of his time at Oxford when he started to notice early signs of his disease. He was getting more clumsy and fell over several times without knowing why.
Explanation:
none